For the third time in the last four weeks, Microsoft today backed away from a customer cutoff as it postponed enforcement of the Windows 8.1 Update migration deadline until June 10.

On Monday -- and just a day before its May Patch Tuesday slate of security fixes -- Microsoft said consumers have four more weeks to move from Windows 8.1 to Windows 8.1 Update before their devices would be barred from receiving further patches. The deadline change was the third in the past month, following an earlier Windows 8.1 Update extension for business users and a surprise update on May 1 for Windows XP after Microsoft had officially retired the aged OS.

"We've decided to extend the requirement for our consumer customers to update their devices to the Windows 8.1 Update in order to receive security updates another 30 days to June 10," said Microsoft spokesman Brandon LeBlanc in a Monday blog. "As noted previously, consumer customers who do not update their Windows 8.1 devices to the Windows 8.1 Update by this new deadline will no longer receive updates."

LeBlanc explained the decision in only general terms, saying that, "While we believe the majority of people have received the update, we recognize that not all have."

It was probable that Microsoft's telemetry was the basis for the move, as the company detects devices' operating systems when those systems query Windows Update, the default patch providing service for consumers and small businesses. The implication was that there were more devices still on Windows 8.1 than Microsoft wanted.

When Microsoft launched Windows 8.1 Update (Win8.1U) on April 8, it told all customers using Windows 8.1 that they had to upgrade to the new refresh within five weeks, or by May 13. Failure to do so, Microsoft said, would block devices running Windows 8.1 from receiving security updates scheduled to ship that day, as well as all future security and non-security updates to the OS.

Business customers howled, calling the mandate a repudiation of Microsoft's long-standing policy of giving customers 24 months to upgrade to a service pack. Although Win8.1U was not labeled as such, many saw similarities to Microsoft's service packs and believed Win8.1U should hew to that policy.

Within a week, Microsoft changed its tune, and gave companies a three-month extension. Enterprises and other organizations that rely on WSUS (Windows Server Update Services), Windows Intune or System Center Configuration Manager to obtain and deploy patches have until August 12 to migrate from Windows 8.1 to Win8.1U.

At that time, Microsoft repeated its demand that customers who used the consumer-grade Windows Update service had to have Win8.1U in place by May 13.

"We're confident that within the next month, the majority of the remaining customers who haven't updated their devices to the Windows 8.1 Update will be able to do so," LeBlanc said today.

One factor that may have tipped the scales in favor of an extension was the widely-reported trouble many have had in getting Win8.1U to install on Windows 8.1 systems. A very long thread on Microsoft's support forum contains more than 1,100 messages from people who have encountered errors while trying to deploy Win8.1U.

"Okay folks, if you are STILL struggling, STILL can't get this damn update installed and I have not opened a support case [for you]/you do not have a support case open, let's get you into support so they can better understand what's going on," wrote forum moderator Susan Bradley in a message Monday alerting readers of the massive thread that Microsoft had extended the deadline to June 10.

Microsoft declined to comment when asked whether the extension was linked to the problems voiced by customers in the support thread.

On Tuesday, Microsoft will issue eight security updates for Internet Explorer, various versions of Windows and Office. Four of the updates will apply to Windows 8.1. All users currently on Windows 8.1, including those who have already installed Win8.1U, will be able to retrieve and install tomorrow's updates.